In switch/routers, interface identifiers (interface IDs) are used for identifying Layer 3 (L3) Interfaces. In typical switch/routers, the maximum number of interface IDs that have hardware support is fixed due to hardware limitations. For instance, in some switch/routers, the interface IDs are limited to 12-bits in length. Therefore, in those switch/routers, there can only be 4096 unique interface IDs. That is, in those switch/routers, the maximum number of Layer 3 Interfaces that can be supported by hardware is 4096.
The number of L3 Interfaces that would benefit from hardware support may far exceed 4096. Yet, the number of interface IDs that the switch/router can store remains limited due to the high cost of memory, such as Content Addressable Memories (CAMs) that are used for storing such identifiers.
In view of the foregoing, there exists a need for a switch/router where the number of hardware-supported logical interfaces can exceed the number of available interface identifiers.